200-Year Flood Elevations

If a 200-year flood occurred along the east bank of the San Joaquin River, the cities of Lathrop and Manteca, CA would be greatly affected. Water surface elevation is defined by FEMA as the height relative to sea level reached by floodwater within the floodplain. This layer estimates water surface elevations (WSE) east of the San Joaquin River in the event of a 200-year flood. The elevation is measured in feet via the North American Vertical Datum (NAVD 1988). In 2014, the City of Manteca commissioned the layer from Peterson Brustad, Inc. for planning purposes.若圣华金河（San Joaquin River）东岸发生200年一遇洪水，加利福尼亚州的拉瑟普（Lathrop）与曼特卡（Manteca）两市将遭受严重影响。美国联邦应急管理局（FEMA）将水面高程定义为洪泛区内地表洪水相对于海平面的高度。本图层估算了圣华金河东岸遭遇200年一遇洪水时的水面高程（Water Surface Elevation, WSE），其高程以北美垂直基准面1988（NAVD 1988）为基准，单位为英尺。2014年，曼特卡市为开展规划工作，委托彼得森·布罗斯塔德有限公司（Peterson Brustad, Inc.）制作了该图层。